One in 15 people who have robot-assisted surgery on their prostate, kidney or bladder develop a nerve injury resulting from the pressure applied to the body from its positioning on the operating table during the procedure, the study, by the University of Virginia School of Medicine in Charlottesville, reveals, according to Reuters Health.

Robotic surgery requires patients to be tilted steeply, nearly upside down, with their head at the floor and their feet jutting upward. This position provides the surgeon with better traction, the study’s researchers indicated.

But the position also enables gravity to get to work, pulling on the patient, meaning “there's a chance [they] could slide down," the study’s lead author, Dr. Tracey Krupski, told Reuters Health.

"When you slide, you then could be pulling, or having the drag on some of the nerves. It's like a constant pulling on the muscle."

The surgical robot manufacturer has been under fire lately, with the U.S. Food and Drug Administration (FDA) reporting plans to investigate, while, at the same time, lawsuits have been piling up, charging that Intuitive is not adequately training surgeons to use the da Vinci systems, putting patients at risk.

Most recently, a judge in a Washington state court failed to quash one lawsuit against Intuitive, and the company has also had to deal with a flurry of media reports exposing confidential corporate emails that reveal how some company employees were focused more on sales of the $1.5 million to $2 million surgical systems, and were deemphasizing the training aspect.

Krupski and her colleagues reviewed records from 334 robot-assisted urology procedures performed at their institution in 2010 and 2011; these procedures included surgeries related to the prostate, kidney, adrenal gland and bladder.

A total of 22 patients – or from 6% to 7% of the whole – awoke from the procedure with an injury, including weakness, numbness or immobility in the hands or feet. More than half of the injuries went away within one month, while five lasted longer than six months, the team reported in The Journal of Urology, as noted by Reuters Health.

Patients were more likely to be injured during longer procedures, such as those lasting up to five-and-a-half hours; surgeries that lasted about four hours left patients without an injury from their positioning on the tilted operating table.

Doctors and nurses can help to prevent these injuries by paying close attention to what's happening to their patients during surgery, slightly readjusting them when necessary, Krupski said in the Reuters Health report.

Krupski noted that a key finding of her study was that patients need to be made aware of the possibility of nerve injury; this is so that if someone experiences it after surgery, he or she will know what the problem is, as well as the fact that there is a chance it will only be temporary.